JP2011189447A - Collet chuck - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a collet chuck superior in fastening force. <P>SOLUTION: The collet chuck includes a tapered chuck part having an insertion port for inserting a tool, forming a tapered part for expanding an outer diameter toward the tapper body direction to the outside and forming a groove in the circumferential direction on the inside or the outside, a tapered sleeve out-fitted to the tapered chuck part and having the inside engaging with the papered part in a cylindrical shape, a nut out-fitted to the tapered sleeve, installed by threading into the tapered chuck part and moving the tapered sleeve in the axial direction by rotation, and a steel ball arranged between the tapered sleeve and the nut and loaded in an annular recessed part extending in the circumferential direction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a collet chuck, and more particularly to a collet chuck with improved clamping force for gripping a tool.

  In general, a tool such as thread cutting is inserted into a collet chuck of a tapper body, and is tightened from the outside and fixed to the collet chuck. The tapper body is attached to the spindle of the machine tool. When the spindle of the machine tool is rotated at a high speed, the collet chuck expands in the radial direction due to centrifugal force, and the tightening force is weakened due to vibrations when processing the workpiece. When the tightening force is weakened, the processing accuracy is lowered. Therefore, it is desired to improve the tightening force of the collet chuck.

  As shown in Patent Document 1, the collet chuck has a cylindrical tapered collet into which a shaft of a tool is fitted inside a chuck cylinder. The tool is fixed by tightening the taper collet from the outside with a tightening nut. The taper collet has a problem in that the vicinity of the entrance into which the tool is inserted is thick, so that even if it is tightened with a tightening nut, the tightening is not sufficient.

Utility Model Publication No. 7-27712

  An object of the present invention is to provide a collet chuck excellent in clamping force.

  The collet chuck according to the present invention has an insertion port into which a tool is inserted, a tapered portion whose outer diameter increases toward the tapper body direction is formed on the outer side, and a groove is formed on the inner or outer circumferential direction. The taper chuck portion, the taper sleeve that is externally attached to the taper chuck portion, and that has a cylindrical shape that engages the taper portion on the inside, is externally attached to the taper sleeve, and is screwed onto and attached to the taper chuck portion. A nut for moving the taper sleeve in the axial direction, and a steel ball loaded in an annular recess extending in the circumferential direction provided between the taper sleeve and the nut.

  The taper chuck portion is provided with a cut extending in the axial direction by dividing the periphery of the insertion slot into a plurality of portions.

  The concave portion of the nut has a V-shaped cross section.

  According to the collet chuck of the present invention, since the groove is provided in the circumferential direction inside or outside the taper chuck portion, the wall thickness is reduced and the insertion port side is easily elastically deformed, and the taper chuck portion is in close contact with the tool. Can be tightened. Further, since the tapered portion is thinner on the insertion port side than the main shaft side, the tool can be securely tightened. If the taper sleeve is moved in the main shaft direction with the nut, the tightening force can be increased. Conversely, if the taper sleeve is moved in the direction of the insertion port, the tightening force can be decreased.

  The taper chuck part has a notch that extends in the axial direction by dividing the periphery of the insertion slot into multiple parts, so that the taper chuck part is easily deformed by elastically deforming the taper chuck part together with the groove provided in the inner or outer circumferential direction. it can. Thereby, the tightening force of the taper chuck portion can be further strengthened.

  Since the steel ball is provided between the taper sleeve and the nut, the taper sleeve can be moved in the axial direction when the nut is rotated. At this time, since the cross section of the recess provided in the nut is V-shaped, the contact area between the steel ball and the nut can be reduced to reduce the frictional resistance. That is, the nut can be easily rotated.

It is a schematic diagram of a collet chuck according to the present invention. It is the front view which looked at the taper chuck | zipper part of FIG. 1 from the A direction. It is a perspective view which shows the end of a common tool.

  Hereinafter, the collet chuck of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic view of a collet chuck according to the present invention. As shown in FIG. 1, the collet chuck 1 has a head portion 16 connected to a tapper body 14, a tool 3 is inserted into a cylindrical taper chuck portion 2 from an insertion port 13, and is tightened from the outside to fix the tool 3. To do. In the taper chuck portion 2, a taper portion 10 whose outer diameter increases toward the tapper body 14 is formed on the outer side. Further, the taper chuck portion 2 is formed with a groove 7 extending in the circumferential direction inside or outside. In this embodiment, grooves are provided on both the inside and outside. The taper sleeve 4 has a cylindrical shape, is externally mounted on the taper chuck portion 2, and the inside engages with the taper portion 10 of the taper chuck portion 2. The nut 5 is mounted on the taper sleeve 4 and is screwed onto the taper chuck portion 2. The nut 5 moves the taper sleeve 4 in the axial direction by rotation. Therefore, annular recesses 11 and 12 extending in the circumferential direction are provided between the taper sleeve 4 and the nut 5 so as to face each other, and the steel balls 9 are loaded in the recesses 11 and 12.

  As shown in FIG. 1, the taper portion 10 between the taper chuck portion 2 and the taper sleeve 4 is increased in diameter toward the tapper body 14 at an inclination angle of 1 to 20 degrees, and the insertion port 13. The diameter decreases in the direction of.

  The groove 7 of the taper chuck portion 2 may have a concave cross section such as a semicircular shape, a U shape, or a V shape. Here, the depth of the groove 7 is ¼ of the thickness of the taper chuck portion 2. Not limited to this, the depth of the groove 7 may be 1/10 to 9/10 of the wall thickness. The width of the groove 7 is desirably 0.5 mm or more, and is 0.8 mm here. The groove 7 was formed at a 2D position from the insertion port 13 toward the tapper body 14 when the diameter of the tool was D. The position of the groove 7 can be in the range of 1 to 5D. The groove 7 is provided on the inner periphery or the outer periphery. Here, it provided in both inner periphery and outer periphery. Since the groove 7 facilitates elastic deformation of the taper portion 10 of the taper chuck portion 2, the tool 3 can be pressed and firmly held.

  The concave portion 11 of the taper sleeve 4 has a semicircular shape. The recess 12 of the nut 5 was V-shaped. Since the shape of the recess 12 is V-shaped, the contact area is small and the nut 5 can be easily rotated. The steel ball 9 is introduced from a hole on one side of the nut 5. The hole is closed with a sealing screw 15 after, for example, 20 steel balls are introduced.

  A square hole portion 6 is integrally formed on the upper portion of the taper chuck portion 2. A square head 3a (see FIG. 3) of a tool is inserted into the square hole portion 6. Thereby, torque transmission performance can be improved. Although the square hole portion 6 is a square through hole, a hole with a bottom may be used.

  When the nut 5 is rotated in one direction, the nut 5 is screwed into the taper chuck portion 2, so that the nut 5 moves in the direction of the tapper body 14, for example. Thereby, the steel ball 9 is also moved. The taper sleeve 4 is also moved in the direction of the tapper body 14 by the movement of the steel ball 9. Thereby, the taper part 10 of the taper sleeve 4 presses and tightens the taper chuck part 2. In this way, the tool 3 can be fixed to the taper chuck portion 2. When the nut 5 is rotated in the other direction, the tightening can be loosened.

  FIG. 2 is a front view of the taper chuck portion of FIG. 1 viewed from the A direction. The taper chuck portion 2 has cuts 8 divided into three in the circumferential direction of the insertion port 13. The division is not limited to three divisions, and can be divided into two to six divisions. The length of the cut 8 in the axial direction was about 3D from the insertion port 13. The length of the notch 8 in the axial direction can be 1 to 5D (D is the diameter of the tool). Since the notch 8 is provided, the taper chuck portion 2 is elastically deformed to be easily bent, and the shaft 3b (see FIG. 3) of the tool can be securely gripped.

  In this embodiment, the overall length of the collet chuck 1 is 62 mm, the outer diameter of the nut 5 is 26 mm, and the diameter of the steel ball 9 is 3 mm.

  The present invention is suitable as a collet chuck having a strong tightening force.

DESCRIPTION OF SYMBOLS 1 Collet chuck 2 Tapered chuck part 3 Tool 3a Square head 3b Shaft 4 Tapered sleeve 5 Nut 6 Square hole part 7 Groove 8 Notch 9 Steel ball 10 Tapered part 11 Recessed part (taper sleeve side)
12 Recess (Nut side)
13 Insertion Port 14 Tapper Body 15 Sealing Screw 16 Head

Claims (3)

A tapered chuck part having an insertion port into which a tool is inserted, a tapered part having an outer diameter expanding toward the tapper body direction on the outside, and a groove formed in the inner or outer circumferential direction;
A taper sleeve that is externally mounted on the taper chuck portion, is cylindrical, and the inside engages with the taper portion;
A nut that is externally mounted on the taper sleeve, is screwed onto the taper chuck portion, and is moved in the axial direction by rotation;
A collet chuck, comprising: a steel ball loaded in an annular concave portion provided between the taper sleeve and the nut and extending in a circumferential direction.
The collet chuck according to claim 1, wherein the taper chuck portion is provided with a notch extending in the axial direction by dividing the periphery of the insertion port into a plurality of portions.
The collet chuck according to claim 1, wherein the recess of the nut has a V-shaped cross section.

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